A rechargeable battery or storage battery is typically a group of one or more electrochemical cells. They are sometimes known as secondary cells because their electrochemical reactions are electrically reversible. Rechargeable batteries come in many different shapes and sizes. Several different combinations of chemicals are commonly used, including: lead-acid, nickel cadmium (NiCd), nickel metal hydride (NiMH), lithium ion (Li-ion), and lithium ion polymer (Li-ion polymer).
Rechargeable batteries are used for portable consumer devices (e.g., smart phones, tablets, laptop computers, notebook computers, etc.), vehicles (such as motorized wheelchairs, golf carts, etc.), tools, uninterruptible power supplies, etc. Emerging applications in hybrid electric vehicles and electric vehicles are driving the technology to reduce cost and weight and increase lifetime. The present invention will be described with reference to a rechargeable battery used in portable consumer devices such as laptop computers, it being understood that the present invention should not be limited thereto.
The energy used to recharge batteries usually comes from a battery charger that provides a source of charging current. Chargers take from a few minutes (rapid chargers) to several hours to charge a battery. During the charging process, charging current is often measured and monitored for a variety of reasons. Charged energy flows from the batteries to one or more loads such as a central processing unit (CPU), backlight, hard disk drive (HDD), etc. During the discharge process, discharging current is often measured and monitored for a variety of purposes.
The use of the same reference symbols in different drawings indicates similar or identical items.